ul {
  width: 100%;
  height: 60px;
  position: fixed;
  left: 0;
  bottom: 0;
  li {
    width: 25%;
    height: 60px;
    float: left;
    text-align: center;
    background: #ccc;
    line-height: 60px;
  }
  .active {
    background: #58bc58;
  }
}
